Multiple dengue serotypes and high frequency of dengue hemorrhagic fever at two tertiary care hospitals in Lahore during the 2008 dengue virus outbreak in Punjab, Pakistan

Abstract

The objective of this study was to investigate the clinical characteristics of patients with dengue viral infection during the 2008 outbreak in Lahore in order to better understand the clinical pattern and severity of disease in Lahore. We analyzed the clinical characteristics of 110 patients infected with dengue virus; data were collected on standardized data collection sheets at two tertiary care hospitals from September to December 2008. Dengue infection was confirmed serologically or by real-time polymerase chain reaction (RT-PCR). Out of the total of 110 dengue infected patients, 70 were male and 40 were female. The most common symptoms included fever (100%), myalgia (68.2%), headache (55.5%), nausea (39.1%), skin rash (53.6%), mucocutaneous hemorrhagic manifestations (58.2%), and ocular pain (20%). Classic dengue fever (DF) was seen in 41.8% of the patients, 56.4% had dengue hemorrhagic fever (DHF), and only 1.8% developed dengue shock syndrome (DSS). The mean duration of fever was 6 days. Thrombocytopenia, leukopenia, and abnormal aspartate aminotransferase (AST)/alanine aminotransferase (ALT) were more frequently encountered in DHF and DSS as compared to DF. Viral RNA detection was done by RT-PCR in 17 patients. Ten patients had DEN4, five had DEN2, and two had DEN3 serotypes. The majority of the patients recovered completely without complications. The high frequency of DHF during the 2008 outbreak and the presence of three different dengue serotypes, emphasize the need to prevent and control dengue infection. Health authorities should consider strengthening surveillance for dengue infection, given the potential for future outbreaks with increased severity. It is also suggested that primary care physicians should be educated regarding recognition of DHF and to identify patients at high risk of developing DHF and DSS.